Since the inception of the LAMMP, pulsed laser microbeams have been utilized to produce cellular effects ranging from reversible transient poration of the plasma membrane to total annihilation of organelles and chromosomes. The specific aims of this project are 1) Develop techniques to quantify microbeam spot size and pulse energy, 2) Characterize the surface morphology of lesions created by microirradiation and ablation of subcellular targets and determine its variability with laser wavelength, radiant exposure, numerical aperture (NA) and pulse duration, 3) Quantify material removal produced by the microablation process and determine its dependence on laser wavelength, radiant exposure, NA and pulse duration, 4) Develop an interferometric system to measure the displacement of particles confined within an optical trap with nanosecond temporal resolution and nanometer spatial sensitivity, and 5) Integrate the interferometer into the Multipurpose Ablation and Trapping S ystem (MATS) to measure the mechanical transients generated by pulsed microbeam ablation processes.